Find DHCPv6 server's IPv6 address

I want to find out the DHCPv6 server's ip address in the network. I went through the lease files but could find only duid/server-id and not the IPv6 address of the dhcp server. And I couldn't find any commands to get that information. Is there a way to get the DHCPv6 server's IPv6 address?

   If I configured my machine to get an IPv4 dhcp address, I can see the lease files having the dhcp server's address. This made me think.. whether DHCP6 servers really expose their IPv6 addresses? 

   Basically looking for commands or system utility apis to get DHCPv6 server's IPv6 address in suse\(sles11,sles12,sled\) and red-hat\(rhel6.8 and rhel7\).

Thanks in advance for your help..